131665819 has 2 divisors, whose sum is σ = 131665820. Its totient is φ = 131665818.

The previous prime is 131665811. The next prime is 131665837. The reversal of 131665819 is 918566131.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 131665819 - 2³ = 131665811 is a prime.

It is a super-2 number, since 2×131665819² = 34671775785881522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (131665811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65832909 + 65832910.

It is an arithmetic number, because the mean of its divisors is an integer number (65832910).

Almost surely, 2^131665819 is an apocalyptic number.

131665819 is a deficient number, since it is larger than the sum of its proper divisors (1).

131665819 is an equidigital number, since it uses as much as digits as its factorization.

131665819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 40.

The square root of 131665819 is about 11474.5727153563. The cubic root of 131665819 is about 508.7342944400.

The spelling of 131665819 in words is "one hundred thirty-one million, six hundred sixty-five thousand, eight hundred nineteen".